Ding Qian, Lin Tuo, Wu Manfeng, Yang Wenqing, Li Wanqi, Jing Yinghua, Ren Xiaoqing, Gong Yulai, Xu Guangqing, Lan Yue
Department of Rehabilitation Medicine, Guangzhou First People's Hospital, School of Medicine, South China University of Technology, Guangzhou, China.
Sichuan Provincial Rehabilitation Hospital, Chengdu University of Traditional Chinese Medicine, Chengdu, China.
Front Cell Neurosci. 2021 Mar 12;15:653487. doi: 10.3389/fncel.2021.653487. eCollection 2021.
Brain-computer interface (BCI) training is becoming increasingly popular in neurorehabilitation. However, around one third subjects have difficulties in controlling BCI devices effectively, which limits the application of BCI training. Furthermore, the effectiveness of BCI training is not satisfactory in stroke rehabilitation. Intermittent theta burst stimulation (iTBS) is a powerful neural modulatory approach with strong facilitatory effects. Here, we investigated whether iTBS would improve BCI accuracy and boost the neuroplastic changes induced by BCI training. Eight right-handed healthy subjects (four males, age: 20-24) participated in this two-session study (BCI-only session and iTBS+BCI session in random order). Neuroplastic changes were measured by functional near-infrared spectroscopy (fNIRS) and single-pulse transcranial magnetic stimulation (TMS). In BCI-only session, fNIRS was measured at baseline and immediately after BCI training. In iTBS+BCI session, BCI training was followed by iTBS delivered on the right primary motor cortex (M1). Single-pulse TMS was measured at baseline and immediately after iTBS. fNIRS was measured at baseline, immediately after iTBS, and immediately after BCI training. Paired-sample -tests were used to compare amplitudes of motor-evoked potentials, cortical silent period duration, oxygenated hemoglobin (HbO2) concentration and functional connectivity across time points, and BCI accuracy between sessions. No significant difference in BCI accuracy was detected between sessions ( > 0.05). In BCI-only session, functional connectivity matrices between motor cortex and prefrontal cortex were significantly increased after BCI training ('s < 0.05). In iTBS+BCI session, amplitudes of motor-evoked potentials were significantly increased after iTBS ('s < 0.05), but no change in HbO2 concentration or functional connectivity was observed throughout the whole session ('s > 0.05). To our knowledge, this is the first study that investigated how iTBS targeted on M1 influences BCI accuracy and the acute neuroplastic changes after BCI training. Our results revealed that iTBS targeted on M1 did not influence BCI accuracy or facilitate the neuroplastic changes after BCI training. Therefore, M1 might not be an effective stimulation target of iTBS for the purpose of improving BCI accuracy or facilitate its effectiveness; other brain regions (i.e., prefrontal cortex) are needed to be further investigated as potentially effective stimulation targets.
脑机接口（BCI）训练在神经康复中越来越受欢迎。然而，约三分之一的受试者在有效控制BCI设备方面存在困难，这限制了BCI训练的应用。此外，BCI训练在中风康复中的效果并不令人满意。间歇性θ波爆发刺激（iTBS）是一种强大的神经调节方法，具有很强的促进作用。在此，我们研究了iTBS是否会提高BCI准确性并促进BCI训练诱导的神经可塑性变化。八名右利手健康受试者（四名男性，年龄：20 - 24岁）参与了这项分两阶段的研究（仅BCI阶段和iTBS + BCI阶段，顺序随机）。通过功能近红外光谱（fNIRS）和单脉冲经颅磁刺激（TMS）测量神经可塑性变化。在仅BCI阶段，在基线和BCI训练后立即测量fNIRS。在iTBS + BCI阶段，BCI训练后在右侧初级运动皮层（M1）进行iTBS。在基线和iTBS后立即测量单脉冲TMS。在基线、iTBS后立即以及BCI训练后立即测量fNIRS。使用配对样本检验比较运动诱发电位的幅度、皮层静息期持续时间、氧合血红蛋白（HbO2）浓度以及不同时间点的功能连接性，以及各阶段之间的BCI准确性。各阶段之间未检测到BCI准确性的显著差异（> 0.05）。在仅BCI阶段，BCI训练后运动皮层与前额叶皮层之间的功能连接矩阵显著增加（< 0.05）。在iTBS + BCI阶段，iTBS后运动诱发电位的幅度显著增加（< 0.05），但在整个阶段未观察到HbO2浓度或功能连接性的变化（> 0.05）。据我们所知，这是第一项研究iTBS作用于M1如何影响BCI准确性以及BCI训练后的急性神经可塑性变化的研究。我们的结果表明，作用于M1的iTBS不会影响BCI准确性或促进BCI训练后的神经可塑性变化。因此，为了提高BCI准确性或促进其有效性，M1可能不是iTBS的有效刺激靶点；其他脑区（即前额叶皮层）需要作为潜在的有效刺激靶点进一步研究。
